In the five minutes it takes to ask Troy Jones about a sudden shortage of potassium iodide pills to prevent radiation sickness, the North Carolina owner of http://www.nukepills.com already has logged nearly two dozen more orders.

“I’m now getting one every 30 seconds,” said Jones, 46, who has sold out of more than 50,000 doses of pills and liquid in days in the wake of fears of potential nuclear fallout from Japan’s devastating earthquake and tsunami.

Despite expert assurances that nuclear radiation won’t reach the shores of America, demand for potassium iodide has swamped the stocks of all three manufacturers or suppliers approved by the federal Food and Drug Administration for use in the U.S.

Anbex, Inc., of Williamsburg, Va., sold out of IOSAT pills on Monday. Fleming & Co. Pharmaceuticals, of Fenton, Mo., which makes ThyroShield Solution is scrambling to make more. And Recipharm AB, the Swedish firm that makes lower-dose Thyro-Safe tablets estimates it will take weeks to replenish its stock.

“We’ve shipped more private orders in the last three days than we have in the last three years,” said Mark Quick, the vice president of corporate development for Recipharm.

Big volume, low cost
If anyone can still get potassium iodide, it’s Jones. Since 1999, he’s been what he describes as the world’s leading retailer of the product that blocks the thyroid gland from absorbing radioactive iodine. He typically buys vast volumes at a low cost from manufacturers and then resells them to distributors and consumers for about $10 for a 14-pill pack of 130-milligram tablets online.

Jones’ site says his customers have included government agencies, hospitals, the U.S. Postal Service, the Centers for Disease Control and Prevention and even the Nuclear Regulatory Commission — although an earthquake-harried spokesman at NRC said he didn’t have time to confirm that. Jones says he sold 5.3 million doses of ThyroShield to Kuwait in 2009 when that country’s nuclear fears escalated.

“Nobody buys it as cheap as me,” said Jones, who wouldn’t reveal his markup to msnbc.com. A 2009 NPR report suggested he buys the pills for about 35 cents apiece and sells them for twice that.

As of Tuesday, Jones had a 3,000-order backlog for all potassium iodide products and was working feverishly from his Mooresville, N.C., home, which is just across the lake from a nuclear power plant. He hoped to replenish his supply as soon as possible, but admitted it could take weeks because of manufacturing and regulatory delays.

Alan Morris, president of Anbex Inc., which manufactures the IOSET pills, said he hoped to produce and ship about 4.5 million tablets in the next few weeks, but admitted that the Japan disaster caught his company a bit off guard.

"The world seems to be utterly terrified of what's going on in Japan," Morris said. "This is the first time in 30 years that we've been out of stock."

Rates of women who are opting for preventive mastectomies, such as Angeline Jolie, have increased by an estimated 50 percent in recent years, experts say. But many doctors are puzzled because the operation doesn't carry a 100 percent guarantee, it's major surgery -- and women have other options, from a once-a-day pill to careful monitoring.

Many customers are private individuals who help fuel sales of about a quarter million tablets a month. Most clients come from New York, Los Angeles — and Utah, Jones said. And while stockpiling antidotes for a nuclear emergency could seem extreme, Jones said the customers aren’t all the tin-foil hat set.

“I have some nuts, people who swear up and down that the world is going to end May 21,” he said. “Most of them are normal, every-day, see-them-at-the-grocery store people.”

Typical buyers are prudent people who simply like to plan ahead, he said.

“Even if the risk is low, why would I not be prepared?” said Wurdack. “I’m one that protects myself and my family, and apparently a lot of people agree with me.”

How much radiation is dangerous?

Radiation is measured using the unit sievert, which quantifies the amount of radiation absorbed by human tissues. One sievert is 1,000 millisieverts (mSv).

In the U.S., the average person is exposed to about 6.2 millisieverts a year, mostly from background radiation and medical tests.

Facts about radiation exposure:

A person would need to be exposed to at least 100 mSv a year to have an increase in cancer risk. Exposure to 1,000 mSv during a year would probably cause a fatal cancer many years later in five out of every 100 people.

Sources: Reuters; New England Journal of Medicine; American Cancer Society; World Nuclear Association and Taiwan's Atomic Energy Council

Potassium iodide actually protects only against one aspect of nuclear radiation, exposure to radioactive iodine 131. It does not protect generally against other forms of radiation exposure, according to the FDA.

No radiation danger in U.S., experts say
Scientists and nuclear experts say they can’t stress enough that no contamination is expected to reach the U.S. and precautions such as stockpiling potassium iodide are not necessary.

But U.S. Surgeon General Regina Benjamin may have contributed to some public health confusion on Tuesday when she told a reporter that while she wasn't aware of people stocking up, it was right to be prepared.

The Department of Health and Human Services quickly issued a statement clarifying that Dr. Benjamin wasn't recommending that anyone go out and purchase the pills.

“Anyone outside of Japan right now, it would certainly not seem necessary,” said Richard Morin, a professor of Radiologic Physics at the Mayo Clinic and chairman of the American College of Radiology’s Safety Committee.

“There is no need to do it,” added Scott Burnell, a spokesman for the Nuclear Regulatory Commission who notes that the U.S. has never had an emergency that required use or distribution of potassium iodide.

Even Troy Jones believes there will be little actual need for his product:

“I personally do not think anyone on the West Coast is in harm’s way from nuclear radiation from Japan,” he said.